Temperature control system



April 7, 1936. A. c. GRANT TEMPERATURE CONTROL SYSTEM Filed July 22, 1953 gwvozwtoc ARTH UR C. GRANT dam/M1 til UNITED STATES PATENT OFFICE 2,036,368 TEMPERATURE CONTROL SYSTEM cooled during the provision Arthur C. Grant, St.

Paul, Minn, assignor to Minneapolis-Honeywell Regulator Company,

Minneapolis, Minn, a corporation of Delaware Application July 22. 1933. Serial No. 681,728 28 Claims. (01. ass-11) The present invention relates to a temperature control system by which a building or space may be automatically heated during the winter and the summer. One of the objects of the present invention is of a cooling system in which outdoor air is circulated to the building or space to be cooled only in the event that the outdoor temperature is below the desired building or space temperature and particularly when the building or space temperature is above Another object of g of a cooling system cooled in which air the desired value. the invention is the provision for a building or space to be is circulated from a normally cooler part of the building, such as the basement,

if the temperature Of the comes higher than that desired.

A further object of the invention is the provision of a cooling system for a building or space in which air is always circulated in the building or space whenever the same is air being selectively taken from temperature, said above the desired the outdoors or from some cooler portion of the building, such as the basement, dependent upon the temperature of the outside of the invention is the pro- Another object air.

vision of humidity changing means in combination with the aforementioned systems.

Other objects oi the specific combinations and invention include the sub-combinations oi the complete summer-winter system, of the various sub-divisions which the summer-winter For a more vention, reference may thereof, and the manner in change-over is obcomplete understanding of the inbe had to the following description and the accompanying drawing, in

which Fig. l is a schematic representation oi the entire system including connections, and

Fig. 2 is a sectional view t-t of Fig. 1.

Referring to Fig.

to control both in i of the drawing, or space the temperature of which the summer and in the winter the details of the electrical taken about on line the building it is desired is herein partially shown as comprising a room ill and the usual of course has at basement ll, which basement least a portion thereof below the surface of the ground as is usual in building construction.

The temperaturercontrol means of the instant invention'includes a heating means herein shown as a warm air furnace it which is heated by a gas burner (not shown) to which gas is supplied by a gas pipe it controlled by an electrically operated gas valve i lof ordinary construction. A du lowing air to pass ct i5 is herein shown for alirom theroom ill into the building or space bemovement of basement although it will be appreciated that under certain conditions this duct I! may be omitted since the natural filtration between the room i0 and basement ll may allow sufiicient air to pass therebetween. An intake duct i6 supplies air to the furnace l2 and is provided with two branches, one branch i'l being in communication with the basement I l and the other branch i8 beingin communication with the outdoor atmosphere. A blower motor l9 operates a blower 20 through a driving connection 2| so as to force air through the furnace i2 and into a discharge duct 22 which communicates with the room ID. A damper 23 is adapted to selectively close off the outdoor inlet duct I8 or the basement inlet duct I1 and is controlled by a damper motor 24 which operates a crank arm 25 that is connected to a crank 26 by means of a link 2i. With the parts in the position shown, when the blower motor i9 is operating, air is drawn into basement inlet duct ll, passes through the furnace i2 and is discharged into room it through discharge duct 22. When the damper 23 is moved to its other position and the blower motor it is operating, outdoor air is taken into the outdoor intake duct it, passes through furnace it and discharges into room ill by means of discharge duct i2. Air filters 26 may be placed in inlet duct it if it is desired to filter and clean the incoming air.

The damper motor 24 is of a well-known type in which current is supplied thereto by line wires 28 and which is additionally provided with three control wires (to be hereinafter specifically referred to) arranged so that completion of the circuit between two of them causes a one half revolution of crank arm 25 to move damper it to its other position, whereas completion of the circuit between two other of the three control wires causes crank arm 25 to return to the position shown in the drawing, all in a manner now well known to those skilled in the art.

The system includes a high limit switch it, a blower switch it and a manually operable switch it. The high limit switch it and blower switch it are thermostatically controlled by the temperature oi the air in furnace it or discharge duct it in the usual manner and the arrangement is preferably such as shown in John P. Kierchbaum application Ser. No. 678,439 filed June 30, 1933, so that manipulation of a single adjusting handle to summer-position closes man" ual switch 32, adjusts high limit switch 3t so that it normally remains open-circuited throughout the summer and adjusts blower switch iii so that it remains closed throughout the summer upon normal temperature fluctuations whereas the adjusting handle to the winterposition opens the manual switch it and sets limit switch 30 and blower switch it at the proper desired and usual operating temperatures for winter-operation. While the thermostatic switching mechanism that includes switches 30 and 3| preferably takes the form disclosed in said Kriechbaum application, it may well comprise the simpler arrangement shown in Fig. 2. A case H is therein shown as being provided with a tubular extension I which extends into the -bonnet N2 of the furnace l2. A thcrmostati" element 3 has one of ,its'ends secured to this extension I and its other end secured to a torsion rod 4 that extends through the extension HI and terminates within case H0. A switch arm 5 is secured to the torsion rod 4 and in turn carries the switches 33 and 3|.

The system of the present invention additionally includes a room thermostat herein shown as a bimetallic'volute 33 which moves a contact blade 34 into engagement with cold and hot contacts 35 and 33 respectively upon changes in the temperature of the room It. The room thermostat controls a relay comprising a pull or energizing coil 3'! and deenergizing or bucking coil which coils control an armature 39 that in turn operates switch arms 40, 4| and 42 which are adapted-to engage contacts 43, 44 and 45 when armature 39 is attracted upon energization of energizing coil 31. An outdoor thermostat comprises a bimetallic volute 46 in control of a contact blade 41 adapted to engage cold and hot contacts 43 and 49 respectively.

The humidity changing means comprises a water spray 50 located in the discharge duct 22 and this water spray 50 is supplied with water by a water pipe 5| which is controlled by an electrically operated water valve 52. A humidostat 53. located in or responsive to the relative humidity of the room I0, partially controls the operation of water valve 52 as will hereinafter become apparent.

High voltage supply lines 54 and 55 power to the primary 56 of a step-down transformer 51 having a low voltage secondary 53. A relay coil 59 is connected to secondary 58 through manual switch 32 by wires 60, 6| and 62. Relay coil 59 controls an armature 63 which in turn operates switch arms 64, 35, 66 and 61. Relay coil 59 is energized at the present time by reason of closure of the manual switch 32 with the result that switch arm 64 is engaging a contact 69, switch arm 35 is engaging a contact 69 and switch arm 61 is engaging a contact 10. Whenever relay coil 59 is deenergized to release armature 33, switch arm 64 will disengage contact 63 andmove into engagement with a contact 1|, switch arm 65 will disengage contact 69 and move pp y .into engagement with a contact 12, switch arm 33 will move into engagement with a contact 13, and switch arm 61 will disengage contact 19 and move into engagement with a contact 14. Line wires 54 and 55 also furnish power to the high voltage primary of a step-down transformer 13 having a low voltage secondary 11.

The remaining circuit connections and the detailed manner in which the system of the instant invention operates and functions will be described under the headings and Winter operation".

"Summer operation" Summer operation The apparatus as shown in Fig. 1 of the drawing is operating on the summer cycle in which manual switch 32 is in the closed position, high limit switch 30 is open and remains open under all normal conditions and blower switch 3| is closed and remains closed under all normal conditions. As previously pointed out, the operation of manual switch 32 and adjustment 01' high limit engagement with cold contact 35. Likewise, the

outdoor temperature is relatively high since it will beobserved that contact blade 41 is in engagement with its hot contact 49. A circuit has therefore been closed to damper motor 24 which circuit includes a wire 18, arm 61, contact 13, wire 13, bimetallic volute 46, contact blade 41, hot contact 49, wire 80 and wire 8|. Closure of this circuit has operated crank arm 25 to the position shown wherein damper 23 closes on outdoor inlet duct l3. Q Now if the room temperature should rise, blade 34 will be moved into engagement with the hot contact 36 of the room thermostat and establish an energizing circuit for pull coil 3'! as follows: secondary 11, wire 32, wire 33, contact 69, switch arm 65, wire 84, hot contact 33, contact blade 34, bimetallic volute 33, wire 35, pull coil 31 and wire 86 to the other side of secondary IT. Armature 39 is thereupon attracted and moves switch arms 40, 4| and 42 into engagement with their respective contacts 43, 44 and 45. Engagement of switch arm 4|] with contact 43 establishes a. holding circuit for pull coil 31 which is entirely independent of all other switches and is as follows: secondary 11, wire 82, wire 31, switch arm 43, contact 43, pull coil 31 and wire" to the other side of secondary I1.

will not result in energization of gas valve H inasmuch as high limit switch 33 is always open during the summer. Likewise, engagement of switch arm 4| with contact 44 will not result in energization of water valve 52 irrespective of the relative humidity 01' the room l0 since the circuit to water valve 52 is broken through switch arm 66 and contact 13. If, however, it should be desired to humidify the air during the summertime, the switch arm 36 and contact 13 could well be omitted whereupon operation of water valve 52 during the summer would be the same as will be hereinafter described in connection with the winter-operation of the system.

Engagement of switch arm 4| with contact 44 does result in energization of blower motor |9 sinceblower-switch 3| is always closed during the sunmier-operation and this energizing circult is as follows: line wire 55, wire 88, contact 44, switch arm 4|, wire 39, blower switch 3|, wire 93, blower motor l3, wire 9| and wire 92 to line wire 54. Energization of blower motor I9 causes the normally cooler air in basement II to be drawn into basement inlet duct l1, pass through air filters 23, pass through furnace l2 and discharge duct 22 and into theroom Hi. In this manner, there will be a continuous circulation of air from the basement I and into room l0 so long as the room remains too hot and the outdoor temperature remains too high.

In the event that this circulation of basement air to the room l0 lowers the room temperature to such an extent that contact blade 34 returns to the position shown in Fig. 1 of the drawing wherein it is in engagement with the cold C nt t I so blade 34, wire 33, switch arm 34, contact 33, wire :4, wire 35, bucking coil 33, wire 35 and wire 33 to the other side of secondary 11. Energization o1 bucking coil 33 sets up a magnetic flux in opposition to the magnetic flux produced by bucking coil 31 with the result that the two magnetic fluxes neutralize one another and allow armature 33 to return by gravity to the position shown in the drawing. Immediately upon separation of switch arm 40 from contact 43 both the holding circuit for pull coil 31 and the energizing circuit for bucking coil 33 are interrupted so that the parts all assume the positions shown in the drawing. Separation of switch arm 4| from contact 44 deenergizies blower motor I! and the circulation or air from basement |l to- I room I0 is interrupted.

There will be times whenthe outdoor-temperature is relatively low causing contact blade 41 to engage cold contact 43. This will occur particularly during the night. When this condition exists, a new circuit to damper motor 24 including wire 13, switch arm 51, contact 10, wire 13, bimetallic volute 46, contact blade 41, cold contact 43, and wire 31 will be established. This circuit causes damper motor 24 to turn crank arm 25 through one half revolution whereupon damper 23 is moved to its other position to close off basement inlet duct l1 and open outdoor inlet duct l8. Now if the room temperature becomes excessive and contact blade 34 engages hot contact 35, blower l9 will again be put into operation as previously described but air will now be taken from the outdoors through outdoor inlet duct I8 and circulated to the room l0 in order to lower the temperature thereof.

From the foregoing description of the operation, it will be seen that blower motor i3 is operated whenever the room temperature becomes excessive in the summer and the damper 23 is selectively positioned to allow air to be circulated to room |0 either from the basement II or from the outdoors, depending upon the outdoor temperature. Preferably the outdoor thermostat is so adjusted that outdoor air may be circulated to the room |0 whenever the room I0 is too hot and whenever the outdoor temperature is below the desired room temperature but if the outdoor temperature is above the desired room temperature, then the natural cool air of the basement II is circulated to the room |0 in an effort to reduce its temperature to the desired value.

It will therefore be seen that the present invention contemplates cooling a building or space by means of the outdoor air whenever the temperature of the outdoor air is sufliciently low. It will also be seen that the present invention contemplates cooling a room or space by circulating air from a naturally cooler portion of the building whenever the temperature of the space to be cooled becomes excessive. The invention furthercontemplates a combination of these two systems whereby outdoor air will be circulated to the space to be cooled when the outdoor temperature is sufilciently low to have a cooling eifect on the space but when the outdoor air is too high in temperature to have a cooling eifect, the basement air is automatically substituted for the outdoor air.

Winter operation During the winter, manual switch 32 is opened, blower switch 3| is adjusted so that it is only closed when the temperature of the air circulated to room I0 is sufficiently high and high limit switch is adjusted so that it is normally closed but opens it the temperature of the air circulated to room l0 or if some other furnace'condition becomes excessive. Opening of manual switch 32 deenergizes relay coil 53 whereupon switch arm 54 moves into engagement with contact 1 I, switch arm 85 moves into engagement with contact '12, switch arm 66 moves into engagement with coritact 13 and switch arm 61 moves into engagement with contact 14. Engagement of switch arm 66 with contact 13 conditions water valve 52 for operation. Engagement of switcharm 61 with contact 14 closes the circuit between control wires 18 and 0| of damper motor 24 and maintains the circuit closed throughout the winter so that the damper 23'will close all outdoor inlet duct l8 irrespective or the outdoor temperature since the circuit to blade 41 has been interrupted by movement of switch arm 61 out of engagement-with contact 10. Disengagement. of switch arm 64 fromcontact 68 and engagement thereof with contact 1| and disengagement of switch arm 65 from contact 59 and engagement thereof with contact 12 reverses the operation of the room thermostat in respect to the pull and bucking coils 31 and 38 as will be apparent as the description of the winter operation proceeds.

-When the room l0 becomes cold, contact blade 34 will engage cold contact 35 to establish an energizing circuit for pull coil 31 as follows: secondary 11, wire 82, wire 83, contact 1 I, switch arm 64, wire 93, cold contact 35, contact blade 34, bimetallic volute 33, wire 85, pull coil 31 and wire 35 to the other side of secondary 11. It will be i noted that pull coil 31 is energized when the room temperature is too low in the winter whereas pull coil 31 is energized when the room temperature is too high in the summer. Energization of pull coil 31 moves switch arms 40, 4| and 42 into engagement with contacts 43, 44 and 45 as before pointed out. Engagement of switch arm with contact 43 establishes the heretofore described holding circuit for pull coil 31 which is independent of all other switches. Engagement of switch arm 42 with contact energizes gas valve l4 to supply gas to the furnace |2 by a circuit as follows: line wire 55, wire 33, contact 45, switch arm 42, wire I00, high limit switch 30, wire I 0|, gas valve I4 and wire I02 to line wire 54. Heat will therefore be supplied to the furnace l2 provided the temperature thereof or the temperature of the air to be circulated to the room In is not already excessive so as to cause opening of limit switch 30.

Engagement of switch arm 4| with contact 44 will condition. blower motor IQ for operation whenever the temperature of the air to be circulated to room 0 is sufficiently high as indicated by closure of blower switch 3| and the clo sure of blower switch 3| taken together with engagement of switch arm 4| with contact 44 conditions water valve 52 for operation at the command of the humidostat 53. If blower switch 3| now closes, blower motor I9 will be energized by the circuit previously described in connection with the summer operation of the system.

If the relative humidity of the room I0 is too low at any time that blower motor I9 is in operation, the water valve 52 will be energized to supply water to the spray by a circuit as fol- It will be noted that during the winter, blower motor l9 can only operate when the room is cold and when blower switch 3-] is closed and it will also ,be noted that water can only be supplied to spray it when blower motor I3 is operating and when the relative humidity to which humidostat 53 responds is below the desired point.

If the temperature of the furnace I2 or of the air delivered as room it should become excessive, limit switch 30 will open in the usual manner to deenergize gas valve l4 and turn of! the supply of gas to the furnace.

Whenever the room temperature rises to the desired point, contact blade 3| will engage hot contact 36 to energize bucking coil 33 by the following circuit: secondary ll, wire 32, wire 31, switch arm 40, contact 43, wire 35, bimetallic volute 33, contact blade 34, hot contact 38, wire 84, switch arm 65, contact 12, wire 35, bucking coil 38, wire 93, and wire 33 to the other side of secondary Tl. Energization of bucking coil 33 allows armature 33 and the associated switch arms to return to the position shown in the drawing in the manner described in connection with the summer operation or the system so as to render water valve 52, blower motor l3 and gas valve i4 inoperative until the room l0 again becomes cold and causes contact blade 34 to again engage cold contact 35. v

From the foregoing description of the winter operation of this system, it will be noted that the system of the present invention provides a year around temperature control which operates to heat a room or space in the winter time and to cool it in the summer time and the change-over between summer and winter operation is simply accomplished by the manual operation of switch 32, blower switch 3| and high limit switch 33, all of which may be controlled by a single operation if desired in the manner set forth in the aforementioned Kriechbaum application.

While a specific embodiment of this complete summer-winter control system has been herein described. it will be understood that changes can be readily made in either the summer-operation or in the winter-operation or in the combination of the two systems and I therefore only intend to be limited in the purview of the appended claims.

I claim as my invention:

1. A system of the class described, comprising, in combination, a space to be cooled, a duct connecting said space to the outside atmosphere, an electrically operated blower for circulating air from the outside atmosphere through said duct and into said space, a thermostatic switch responsive to the temperature of the outside atmosphere for preventing circulation of outside air into said space if the temperature of the outside atmosphere is above a predetermined value and manually operable switching means associated with said thermostatic switch for rendering the same incapable of permitting circulation of outside air to said space irrespective of the outside temperature.

2. A system of the class described, comprising, in combination, a space to be cooled, a duct connecting said space to the outside atmosphere, means for circulating air from the outside atmosphere through said duct and into said space, a space temperature responsive thermostat for operating the circulating means when the temperature of the space rises above a given value, thermostatic means responsive to the temperature of the outside atmosphere for preventing circulation of air from the outside atmosphere and same incapable of permitting circulation of outside air to said space irrespective of the temperature of the outside air.

3. A system of the class described, comprising irr combination, a first space which it is desired to cool, a second space located at least partially below the surface of the ground, duct means inter-connecting said first space, the second space and the outside atmosphere, damper means cooperating with said duct means and operable to selectively connect said first space with the second space or the outdoors, a thermostat responsive to outdoor temperature in control of said damper means to connect the outdoors with the first space when the outdoor temperature is below a given value and to connect the second space to the first space when the outdoor temperature rises above said value, circulating means for circulating air through said duct means and into said first space, and a thermostat responsive to the temperature of said first space for operating said circulating means when the temperature of the first space is above a predetermined value.

4. A system of the class described, comprising in combination, a first space which it is desired to cool, a second space located at least partially below the surface of the ground, duct means inter-connecting said first space, the second space and the outside atmosphere, damper means cooperating with said duct means and operable to selectively connect said first space with the second space or the outdoors, a damper motor operatively connected to the damper means, a thermostat responsive to outdoor temperature in control of said damper motor to operate said damper means to connect the outdoors to the first space when the outdoor temperature is below a given value and to connect the second space to the first space when the outdoor temperature rises above said value, a blower for circulating air through said duct means and into said first space, and a thermostat responsive to the temperature of said first space for operating said blower when the temperature of the first space is above a predetermined value.

5. A system of the class described, comprising in combination, a first space which it is desired to cool, a second space located at least partially below the surface of the ground, duct means interconnecting said first space, the second space and the outside atmosphere, damper means cooperating with said duct means and operable to selectively connect said first space with the second space or the outdoors, a thermostat responsive to outdoor temperature in control of said damper means to connect the outdoors to the first space when the outdoor temperature is below a given value and to connect the second space to the first space when the outdoor temperature rises a predetermined amount above said value, an electrically operated blower for circulating air through said duct means and into said first space, and thermostatic switching means responsive to the temperature of said first space for operating said blower when the temperature of the first space is above a predetermined value.

6. A temperature control system of the class described, comprising, in combination, a space the temperature of which it is desired to control, duct means connecting said space to the outdoors, damper means assoclated with said duct accuses means and operable to permit or prevent circulation of air from the outdoors to said space, a thermostat responsive to the outdoor temperature for operating said damper means to prevent circulation of air from the outdoors to said space a blower for circulating air to said space, means for heating the air circulated to the space, connections between the space thermostat and blower for operating the latter when the space temperature falls below the desired value, manually operable means for changing said connections in such manner that the space thermostat operates said blower when the space tem-- perature becomes too high in the summer, a thermostat responsive to outdoor temperatures, damper means controlled by said outdoor theirmostat for permitting circulation oi outdoor air to said space when the outdoor temperature is below the desired space temperature in the sumill) mer, and connections between said manually operable means and outdoor thermostat for rendering the latter incapable of operating the damper means to permit circulation of outdoor air to said space when said manually operable means is in winter position.

a. In combination, a space the temperature of which it is desired to control, a thermostat responsive to the temperature of the space, a blower for circulating air to said space, means for heating the air circulated to the space, connections between the space thermostat, heating means, and blower for operating the heating means and blower when the space temperature rails below the desired value, high limit means responsive to the temperature or the heated air for preventing operation or the heating means if the temperature of the heated air is too'high, manually operable means for changing said connections in such manner that the space ther rnostat operates said blower when the space tamperature becomes too high in the summer and for adjusting said high limit means to prevent operation of the heating means in the simmer, a thermostat responsive to outdoor temperatures, damper means controlled by said outdoor ethermostat for permitting circulation of outdoor air to said space in the summer by said blower when the outdoor temperature is below the desired space temperature and connections associated with said damper means and manually operable means for preventing operation of the damper means to permit circulation at outdoor air to a said space in the winter under the control at Eli said outdoor thermostat.

9. In combination, a space the temperature off which it is desired to control, a thermostat re sponsive to the temperature oil the space, a blower for circulating air to said space, means for heating the air circulated to the space, connections between the space thermostat and blower for operating the latter when the space temperature falls below the desired value, manually operable means for changing said connections in such manner that the space thermostat operates said blower when the space temperature becomes too high in the summer, a thermostat responsive to outdoor temperatures, damper means controlled by said outdoor thermostat for permitting circulation of outdoor air to said space when the outdoor temperature is below the desired space temperature in the summer and for preventing such circulation upon operation of said manually operable means to winter position, humidity changing means associated with the circulated air, a humidistat responsive to the relative humidity in said space, and connections between said humidistat, space thermostat and humidity changing means.

10. In combination, a first space the temperature or which is to be controlled, a second space which is generally cooler in the summer than said first space, a thermostat responsive to the temperature of said first space, a blower for circulating air from said second space to said first space, means for heating said air, connections between said space thermostat, blower, and heating means for operating the blower and heating means when the temperature of said first space drops to a predetermined minimum in the winter, and manually operable means for rearranging said connections in such manner that the blower is operated upon rise in the space temperature to a given value and the heating means is rendered inoperative in the summer, whereby the air is circulated from said cooler second space to said first space at the command of said space thermostat in the summer.

ii. in combination, a first space the temperature of which is to be controlled, a second space which is generally cooler in the summer than said first space, a thermostat responsive to the tom-- perature of said first space, a blower ior circulating air from said second space to said first space, means for heating said air, connections between said space thermostat, blower, and heating means lor operating the blower and heating means when the temperature or said first space drops to a predetermined minimum in the winter, high limit means responsive to the temperature oi the circulated air i'or preventing operation oi the heating means it the temperature or the heated air is too high, and manually operable means ior rearranging said connections and adjusting said high limit means in such manner that the blower is operated upon rise in the space temperature to a given value and the heating means is rendered inoperative during the summer, whereby the air is circulated from said cooler second space to said first space at the command or said space thermostat in the summer,

id. in combination, a first space the temperature of which is to be controlled, a. second space which is generally cooler in the s 1 in: er than said first space, a thermostat responsive to the tern perature of said first space, a blower for circulating air from said second space to said first space, means for heating said air, connections between said space thermostat, blower, and heating means for operating the blower and heating means when the temperature of said first space drops to a predetermined minimum in the winter, a blower controller responsive to the temperature of the heated air for preventing operation or the blower ii the temperature of the. circulated air is below a given value, and manually operable means for rearranging said connections and adjusting said blower controller in such manner that the blower is operated upon rise in the space temdill perature to a given value irrespective of normal fluctuations in the circulated air temperatm'e and the heating means is rendered inoperative whereby air is circulated from said cooler second space to said first space at the command of said space thermostat in the summer.

13. A summer-winter control system of the class described, comprising, in combination. a building including a basement and a-space the temperature of which it is desired to control, duct means inter-connecting said space, basement and the outdoors, damper means associated with said duct means and operable to selectively connect said space with the basement or outdoors. a blower for circulating air through said duct means and into said space, means for heating the air circulated to said space, a space temperature responsive thermostat, connections between the space thermostat and blower for operating said blower upon fall in space temperature to maintain the desired space temperature during the winter, manually operable means for rearranging said connections in such manner that the blower is operated upon rise of the space tem-- perature in the summer, and a thermostat respon-- sive to the outdoor temperature for operating said damper means to connect the outdoors to the space when the outdoor temperature is lower than the desired space temperature in the summer and rendered operable by said manually operable means.

14. A summer-winter control system of the class described, comprising, in combination, a building including a basement and a space the temperature of which it is desired to control, duct means inter-connecting said space, basement and the outdoors, damper means associated with said duct means and operable to selectively connect said space with the basement or outdoors, a blower for circulating air through said duct means and into said space, means for heating the air circulated to said space, a space temperature responsive thermostat, connections between the space thermostat, heating means and blower for operatlng the heating means and blower whereby to maintain the desired space temperature during the winter, manually operable means for rearranging said connections in such manner that the blower is operated upon rise of the space temperature in the summer, a thermostat responsive to outdoor temperature for operating said damper means to connect the outdoors to the space when the outdoor temperature is lower than the desired space temperature in the summer, rendered operative by said manually operable means, humidity changing means associated with said duct means, and a humidostat in control thereof.

15. A summer-winter control system of the class described, comprising, in combination, a building including a space the temperature of which it is desired to control and a basement, a warm air furnace located in the basement, a duct connecting said warm air furnace to the space, duct means interconnecting said warm air furnace, the interior of the basement, and the outdoor atmosphere; an electrically operated blower associated with said furnace and ducts for circulating air through the furnace and into said space, electrically controlled means for heating the air circulating through the furnace, thermostatic switching means responsive to the temperature of the space, connections between said thermostatic switching means, heating means and blower for operating the heating means and a,oas,sss

blower to supply heated airtosaid space when the space temperature falls below the desired value in the winter, a high limit switch in circuit with said heating means and responsive to the temperature of the heated air for preventing operation of the heating means if the temperature of the circulated air becomes too high, a blower switch responsive to the temperature of the circulated air for preventing operation of the blower if the temperature of the circulated air is too low,

manually controlled means for adJusting said high limit switch and blower switch and for rearranging the connections to the space temperature responsive switching means in such manner that operation of the heating means is prevented and the blower is operated upon fall in the space temperature irrespective of normal fluctuations in the temperature of the circulated air, damper means associated with saidduct means and selectively operable to connect said furnace with the outdoor atmosphere or the interior of said basement, and a thermostat responsive to the outdoor temperature adapted to be placed in control of said damper means for connecting the outdoor atmosphere to the furnace when the outdoor temperatune is below the desired space temperature and for connecting the furnace to the interior of the basement when the outdoor temperature is above the desired space temperature during the summer, said manually operable means serving to place said outdoor thermostat in control of said damper means when in summer po sition.

16. A system of the class described, comprising, in combination, a first space which it is desired to cool, a second space normally cooler than said first space in the summer, duct means interconnecting the first space, second space, and the outside atmosphere, means for controlling the circulation of air from the outside atmosphere and from said second space to said first spaceand an outdoor temperature responsive thermostat in control of said means.

17. A system of the class described, comprising, in combination, a first space which it is desired to cool, a second space normally cooler than said first space in the summer, duct means interconnecting the first space, second space, and the outside atmosphere, damper means for controlling I ment and a space the temperature of which it is desired to control, duct means inter-connecting said space, basement and the outdoors, circulating means for causing a circulation of air through said duct means to said space, damper means controlling the flow of air from the outdoors or basement to said space, an outdoor thermostat in control of said damper means for operating the same to permit the circulation of outdoor air to said space in the summer when the outdoor air is below the desired value, means for heating the air delivered to said space in the winter, and manually operable means associated with said heating means and outdoor thermostat for rendering said heating means inoperative when moved to its summer position and for preventing operation 01' said damper means by said outdoorthermostat to permit circulation of outdoor air in the winter when moved to its winter position.

19. In combination, a building including a basement and a space the temperature of which it is desired to control, duct means inter-connecting the space, basement and outdoors, a blower for circulating air through said duct means to said space, electrically operated heating means for heating the air circulated to said space, a space temperature responsive switching mechanism, electrically operated damper means controlling the circulation of air from the outdoors and basement to said space, an outdoor temperature responsive switching mechanism, manually operable switching mechanism having a winter position and a summer position, electrical connections between said space thermostat, heating means and manually operable switching mechanism for enabling said thermostat to operate said heating means when the manually operable switching mechanism is in winter position, and connections between said outdoor thermostat, damper means and manually operable switching mechanism for enabling said outdoor thermostat to operate said damper means to permit circulation of outdoor air to said space when the outdoor air is below the desired space value and the manually operable switching mechanism is in summer position.

20. A cooling system of the class described, comprising, in combination, a building including a space to be cooled and a basement, means in control of the circulation of air from the basement to said space, and an outdoor temperature responsive thermostat associated with said means for controlling the same to permit circulation of air from said basement to said space when the outdoor temperature rises to a given value.

21. A cooling system of the class described, comprising, in combination, a building including a space to be cooled and a basement, duct means connecting said space and basement, damper means for opening said duct means to permit circulation of air from the basement to said space, and an outdoor temperature responsive thermostat associated with said damper means for operating the same to open said duct means when the outdoor temperature rises above a predetermined value.

22. The combination with a first space to be controlled and a second space which is normally cool in the summer, of circulation controlling means in control of the flow of air to the first space from the second space and the outdoors, an outdoor temperature responsive thermostat in control of said circulation controlling means, and means to prevent operation of the circulation controlling means by the outdoor temperature responsive thermostat irrespective of the value of the outdoor temperature.

23. The combination with a first space to be controlled and a second space which is normallycool in the summer, of damper means to control the flow of air to said first space from the second space and the outdoors, an outdoor temperature responsive thermostat in control of said trolling means in control of the circulation of air to the first space from the second space, an outdoor temperature responsive thermostat in control of said circulation controlling means, and means to prevent such control by the outdoo thermostat.

'25. The combination with a first space to be cooled and a second space which isnormally cooler than the first space, of circulation controlling means in control of the flow of air from said second space and the outside atmosphere to said first space, thermostatic means responsive to the temperature of the first space and the outdoors, and connections between said thermostatic means and circulation controlling means to cause circulation of air to said first space when the temperature thereof becomes too high and to select such air from the second space and the outdoors in response to changes in outdoor temperature.

26. The combination with a first space to be cooled and a second space which is normally cooler than the first space, of circulation controlling means in control of the flow of air from said second space and the outside atmosphere to said first space, thermostatic means responsive to the temperature of the first space and the outdoors, connections between said thermostatic means and circulation controlling means to cause circulation of air to said first space when the temperature thereof becomes too high and to select such air from the second space or the outdoors in response to changes in outdoor temperatures, and means to change the control action of the thermostatic means to cause air to be circulated to said first space from said second space upon a fall in the temperature of the first space and irrespective of the temperature of the outdoor air.

27. In combination, circulation controlling means in control of the flow of air to a space, means to humidify such air, a space humidity responsive element to control said humidifying means, a space temperature responsive device to operate the circulation controlling means and to place the humidity responsive element in control of the humidifying means upon a lowering in space temperature, and a single means operable to reverse theaction of the space temperature responsive device on the circulation controlling means and to prevent operation of the humidifying means by the humidity responsive element.

28. A temperature control system of the class described, comprising, in combination, damper means in control of the flow of outdoor air to a space to be controlled, a thermostat responsive to outdoor temperature in control of said damper means to prevent the circulation of outdoor air to the space when the outdoor air temperature is too high in the summer, heating means to heat the air, a space temperature responsive thermostat, and a single means operable to move the damper means to a position to prevent the circulation of outdoor air to said space irrespective of the outdoor temperature and to place the space thermostat in control of the heating means to operate the same upon a fall in space temperature to a predetermined point.

ARTHUR C. GRANT. 

